A conventional two-wheel motorbike generally includes a frame with an engine, a gear box connected with the engine, two wheels connected to two ends of the frame, a handlebar and an outer casing. The engine is fixed to the frame and the output power of the engine is transferred to the real wheel by a chain. The handlebar is able to change the direction of the front wheel. A three-wheel vehicle includes a differential and two transmitting shafts connected with two rear wheels. Obviously, the two-wheel motorbike cannot directly transfer to three-wheel vehicle by the existed frame of the two-wheel motorbike. Therefore, there is no way to use the structure of the two-wheel motorbike to be transferred into a three-wheel vehicle. The user has to order a new three-wheel vehicle and all of the parts of the two-wheel motorbike become useless.
The present invention intends to provide a device that can be directly connected to the frame of the two-wheel motorbike and the engine and a differential are connected to the device, and two transmitting shafts are connected to two rear wheels such that the most of the parts of the two-wheel motorbike can be used for the three-wheel vehicle.